Toner dispenser



Jan. 24, 1967 J. w. WAGNER TONER DI SPENSER 5 Sheets-Sheet 1 Filed July 1, 1965 INVENTOR. JOHN W. WAGNER zw /flzudv' A T TORNE Y Jan. 24, 1967 J. w. WAGNER 3,300,101

TONER DISPENSER Filed July 1, 1965 s Sheets$heet 2 l V NTOR. JOHN WAGNER ATTORNEY Jan. 24, 1967 J. w. WAGNER TONER D I SPENSER 3 Sheets-Sheet 5 Filed July 1, 1965 INVENTOR JOHN W. WAGNER A T TORNEV United States Patent Office Patented Jan. 24, 1967 3,300,101 TONER DISPENSER John W. Wagner, Penfield, N.Y., assignor to Xerox Corporation, Rochester, N.Y., a corporation of New York Filed July 1, 1965, Ser. No. 468,849 3 Claims. (Cl. 222-310) This invention relates to apparatus for dispensing powder or granulated material and, particularly, to xerographic toner dispensing apparatus.

More specifically, the invention relates to a toner dispenser that is particularly adapted for use in a xerographic developing apparatus wherein, in order to develop the electrostatic latent image formed on a xerographic plate, it is required to dust the image with a developer powder, whereby the powder particles are selectively attracted to the charged areas of the plate to form a visible powder particle image of the electrostatic latent image.

In the process of xerography, for example, as disclosed in Carlson Patent 2,297,691, issued October 6, 1942, a xerographic plate, comprising a layer of photoconductive insulating material on a conductive backing is given a uniform electric charge over its surface and is then exposed to the subject matter to be reproduced, usually by conventional projection techniques. This exposure discharges the plate areas in accordance with the light intensity which reaches them and thereby creates an electrostatic latent image on or in the plate coating.

Development of the image is effected with developers which comprise, in general, a mixture of a suitable pigmented or dyed electrostatic powder, herein-after referred to as toner, and a granular carrier material, which latter functions to carry and to generate triboelectric charges on the toner. More exactly, the function of the granular material is to provide the mechanical control to the powder, or to carry the powder to an image surface and, simultaneously, to provide almost complete homogeneity of charge polarity. In the development of the image, the toner powder is brought into surface contact with the coating and is held thereon electrostatically in a pat-tern corresponding to the electrostatic latent image. Thereafter, the developed xerographic image is usually transferred to a support material to which it may be fixed by any suitable means.

In the mixture of toner particles and carrier material, the toner particles, which are many times smaller than the carrier particles, adhere to and coat the surface of the carrier particles due to the electrostatic attraction between them. During development, as the powder coated carrier particles roll or tumble over the xerographic plate carrying an electrostatic image of opposite polarity to the charge on the toner, toner particles are pulled away from the carrier by the charged image and deposited on the plate to form a powder image, while the partially denuded carrier particles pass off the plate. As toner powder images are formed, additional toner particles must be supplied to the developer mixture in proportion to the amount of toner deposited on the plate.

If prints made by the xerographic process have heavy deposits of toner in image areas of good contrast and non-image areas have a gray veiling, the toner concentration in the developer mixture is too great. If the prints have low contrast images, the quantity of toner particles in the developer mixture is insufficient.

In order to continually obtain prints of good quality, the quantity of toner powder in the developer mixture must be held reasonably constant by the addition of toner to the developer mixture in proportion to the amount of toner deposited on the plate.

It is therefore an object of this invention to improve apparatus for dispensing powder or granulated material.

Another object of this invention is to improve toner dispensing apparatus whereby metered amounts of toner are added to the developer mixture in a xerographic machine in proportion to the amount of toner used by the machine to make xerographic copy.

A further object of the invention is to improve a toner dispensing apparatus which will dispense a given amount of toner powder.

Another object of this invention is to improve toner dispensers to prevent agglomerating.

Still another object of this invention is to improve toner dispensers which are capable of dispensing substantially continuously.

These and other objects of this invention are attained by means of a housing for holding the toner material and an escape chute for delivering the toner material out of the' housing and a device for lifting the toner material from the housing to the escape chute for the dispensing thereof.

The present invention contemplates an improvement in dispensing devices wherein an automatic metering arrangement is provided to control the rate of discharge from the dispenser.

For a better understanding of the invention as well as other objects and further features thereof, reference is had to the following detailed description of the invention to be had in connection with the accompanying drawings wherein:

FIG. 1 illustrates schematically a preferred embodiment of a xerographic apparatus adapted for continuous and automatic operation, and incorporating a toner dis penser in accordance with the invention;

FIG. 2 is a perspective view with parts broken away of the toner dispenser constructed in accordance with the present invention; and,

FIG. 3 is an end view with parts broken away of the toner dispenser constructed in accordance with the present invention.

As shown in FIGURE 1, the xerographic apparatus comprises a xerographic plate including a photoconductive layer or light receiving surface on a conductive backing and formed in the shape of a drum which is journaled in a frame to rotate in the direction indicated by the arrow to cause the drum surface sequentially to pass a plurality of xerographic processing stations.

For the purpose of the present disclosure, the several xerographic processing stations in the path of movement of the drum surface may be described functionally as follows:

A charging station at which a uniform electrostatic charge is deposited on the photoconductive layer of the xerographic drum is shown at A. An exposure station at which a light to be reproduced is projected onto the drum surface to dissipate the drum charge on the exposed areas thereof, and thereby forma latent electrostatic image on the copy to be reproduced is shown at B. A developing station, where a xerographic drum is developed is shown at C. A transfer station at which the xerographic powder image is electrostatically transferred from the drum surface to the material is shown at D. A drum cleaning station is shown at E.

The charging apparatus or corona charging device 21 includes a corona discharge array of one or more discharge electrodes that extend transversely across the drum surface and are energized from a high potential source and are substantially enclosed within a shielding member.

The optical scanning or projection assembly consists of a copyboard in the shape of a drum, hereinafter referred to as copy drum 22, which is adapted to support copy to be reproduced and arranged to rotate in light- 3 projection relation to the moving light-receiving surface of the xerographic plate.

Copy fed through paper guides 32 to the copy drum is removably secured thereon by a suitable gripper mechanism for movement therewith in timed relation to the movement of the xerographic dnum whereby a flowing image of the copy is projected onto the xerographic drum. After the copy is scanned it can be released from the copy drum to be transported out of the machine through copy guide 33.

Adjacent to the exposure station is a developing station C in which there is positioned a developer apparatus 35 including a developer housing having a lower or sump portion for accumulating developer material 36. Mounted within the developer housing is a motor driven bucket-type conveyor used to carry the developer material previously supplied to the developer housing to the upper portion of the developer housing from where the developer material is cascaded over a hopper chute onto the drum.

As the developer material cascades over the drum, toner particles of the developer material adhere electrostatically to the previously formed electrostatic latent image areas on the drum to form a visible Xerographic powde rimages are replenished by a toner dispenser off the peripheral surface of the drum into the bottom of the developer housing. Toner particles consumed during the developing operation to formthe xerographic powder image are replenished by a toner dispenser mounted within the developer housing.

Positioned next adjacent to the developing station is the image transfer station D which includes suitable sheet feeding mechanism adapted to feed sheets of paper successively to the xerographic drum in coordination with the presentation of the developed image on the drum at the transfer station.

The next and final station in the device is a drum cleaning station E whereat any powder remaining on the xerographic drum after the transfer step is removed and whereat the Xerographic drums is flooded with light to cause dissipation of any residual electrical charge remaining on the xerographic drum. 7

Removal of residual powder from the xerographic dum is effected by means of a web cleaner device 54 adapted to continuously feed a clean fibrous web material into wiping contact with the xerographic drum.

Suita ble drive means drive the xerographic drum, copy drum and sheet conveyor mechanism at predetermined speeds relative to each other. Suitable drive means are also provided for effecting operation of the developer conveyor mechanism and the toner dispenser of the developing apparatus assembly.

It is believed that the foregoing description is suflicient for the purposes of this application to show the general operation of the xerographic reproducing apparatus. For further details concerning the specific construction of the xerogr aphic apparatus shown, reference is made to Patent No. 3,099,943 issued Sept. 6, 1963 to Roger H. Eichorn et al.

As the developing mixture is cascaded over the xerographic drum, toner particles are electrostatically pulled away from the carrier component of the developer material and deposited on the drum to form xerographic powder images, while the partially denuded carrier particles pass over the drum into the reservoir. As toner powder images are formed additional toner particles must be supplied to the developing mixture in proportion to the amount of toner deposited on the drum. To supply additional toner particles to the developer mixture a toner dispenser is used to accurately meter toner to the developer housing through a suitable opening formed in the top back portion of the outer shell.

Referring now in particular to FIGURES 2 and 3 inclusive, which illustrate a preferred embodiment of the toner dispenser 37, the toner dispenser embodying the instant invention includes a housing 101 for holding the toner particles. The housing 101 has a V-shaped bottom portion therein. Mounted in this bottom portion is an escape chute 103 which has a bottom opening 106 and a top opening 107 which extends into the housing 101. The opening 106 opens to the developer apparatus 35. The top portion of the chute is mounted adjacent the top of the housing 101 above the normally full level of the dispenser as shown in FIGURE 3.

It is by means of this escape chute 103 that the toner particles stored in the toner housing are conveyed to the developing apparatus 35 of the xerographic apparatus. A pair of guides 108 and 110 are mounted in the housing 101 on each side of the chute 103. These guides serve to locate and guide the dispensing wire 112 which dispenses the xerographic toner from the toner dispenser into the escape chute and then onto the developing apparatus. This dispensing wire is shown in the loading or lower position in FIGURE 3 and in the upper or dispensing position in FIGURE 2. The operation of this wire is to be described below.

From the lowermost position of the dispensing wire as shown in FIGURE 3 the wire is moved upward along the slots 109 and 111 of guides 108 and 110. The dispensing wire is moved by means of actuating arms 114 and 116. The actuating arms 114 and 116 are connected to a shaft 120 which is rigidly connected to a slotted element 122. The slotted element is moved by a crank 124 which is continuously rotated by a suitable drive means such as a pulley which may be attached to the eveloper conveyor. Connected to the shaft 120 mounted outside the actuating arms 114 and 116 are a pair of outer agitators 126. Mounted between and through the actuating arms 114 and 116 are a series of inner agitating wires 128 for stirring up the toner as the dispensing wire is raised and lowered in the toner dispenser housing. The outer agitators 126 and the inner agitating wires 128 serve in addition to dispensing wire 112 to prevent agglomeration of the toner particles in the housing.

It is contemplated that crank 124 may be continuously driven or intermittently driven. A separate drive means and/ or a suitable transmission could be used.

The dispensing wire is shown in the raised position in FIGURE 2 and in the lowered position in FIGURE 3. From the lower position the dispensing wire is raised from the bottom of the toner dispenser housing to the top of the housing by means of actuating arms 114 and 1116 thereby agitating the toner, preventing the toner from becoming agglomerated. At the same time, the wire picks up a certain amount of toner on the wire itself. As this wire reaches the top portion or the bend 130 in the guide slots 109 and 111 the wire will move to the left as seen in FIGURE 3.

Any excess toner will be removed by an excess scraper 132, which is pivotally adjusted about pivot pin 138. This excess scraper is adjustable by means of screw 134 and an adjustable nut 135. The spring 137 forces the scraper 132 against the nut 135. It is noted that this scraper can thus be adjusted to provide for the amount of excess toner to be removed from the dispensing wire. It is noted that this nut can be loosened to the extent that no excess toner will be removed from the dispensing wire.

As the dispensing wire moves up along the slots 109 and 111 and it passes the excess scraper 132, the dispensing wire will come to the position shown in FIGURE 2, which is the dispensing position. The toner is dispensed by means of a dispensing scraper 140. The dispensing scraper 140 is mounted on adjustable screw 142 which is attached to secured nut 144. The dispensing scraper is adjustable about pivot pin 146. The toner dispenser may be refilled by means of door pivotally secured to the developer housing.

It is noted that the amount of toner dispensed may be adjusted by means of the excess scraper 132. The adjustment of the dispensing scraper 140 serves to maintain an adjustment to insure that all or a given amount of toner is scraped off the dispensing wire. It is contemplated that the dispensing wire 112 may have a flat portion on the top thereof.

It will be understood that various changes in the details, materials, steps and arrangements of parts, which have 'been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. However, while the invention has been described with reference to the structure disclosed herein, it is not to be confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the scope of the following claims.

What is claimed is:

1. A toner dispenser including:

a housing suitable for holding a quantity of toner material,

an escape chute having an opening at the top thereof and an opening at the bottom thereof extending through the bottom of the housing with the top of the chute located adjacent the top of the housing,

a dispensing wire extending across the length of the housing and movable in the housing,

means for guiding said wire,

said wire being movable in said guide means from a lower portion of the housing to an upper portion of the housing above the opening in the chute whereby said wire agitates the toner in the housing during the movement thereof and accumulates a quantity of toner thereon,

means for lifting the wire, and

a dispensing scraper mounted above the chute for scraping the toner accumulated on the wire into the escape chute.

2. A toner dispenser including:

a housing suitable for holding a quantity of toner material,

an escape chute having an opening at the top thereof and an opening at the bottom thereof extending through the bottom of the housing with the top of the chute located adjacent the top of the housing,

means for dispensing toner extending across the length of the housing and movable in the housing,

means for guiding said dispensing means,

said dispensing means being movable in said guide means from a lower portion of the housing to an upper portion of the housing above the opening in the chute whereby said dispensing means agitates the toner in the housing during the movement thereof and accumulates a quantity of toner thereon,

means for lifting the dispensing means, and

a dispensing scraper mounted above the chute for scraping the toner accumulated on the wire into the escape chute.

3. A housing suitable for holding a quantity of toner material,

an escape chute having an opening at the top thereof and an opening at the bottom thereof extending through the bottom of the housing with the top of the chute located adjacent the top of the housing,

a dispensing wire extending across the length of the housing and movable in the housing,

means for guiding said wire,

said wire being movable in said guide means from a lower portion of the housing to an upper portion of the housing above the opening in the chute whereby said wire agitates the toner in the housing during the movement thereof and accumulates a quantity of toner thereon,

means for lifting the wire,

and a dispensing scraper mounted above the chute for scraping the toner accumlated on the Wire into the escape chute,

and an adjustable excess scraper mounted adjacent the dispensing scraper to remove excess toner from the wire to vary the amount of toner carried to the dispensing scraper.

References Cited by the Examiner UNITED STATES PATENTS 12/1960 Rutkus et al 222-226 X 9/1964 Eichorn et al. 222342 X 

1. A TONER DISPENSER INCLUDING: A HOUSING SUITABLE FOR HOLDING A QUANTITY OF TONER MATERIAL, AN ESCAPE CHUTE HAVING AN OPENING AT THE TOP THEREOF AND AN OPENING AT THE BOTTOM THEREOF EXTENDING THROUGH THE BOTTOM OF THE HOUSING WITH THE TOP OF THE CHUTE LOCATED ADJACENT THE TOP OF THE HOUSING, A DISPENSING WIRE EXTENDING ACROSS THE LENGTH OF THE HOUSING AND MOVABLE IN THE HOUSING, MEANS FOR GUIDING SAID WIRE, SAID WIRE BEING MOVABLE IN SAID GUIDE MEANS FROM A LOWER PORTION OF THE HOUSING TO AN UPPER PORTION OF THE HOUSING ABOVE THE OPENING IN THE CHUTE WHEREBY SAID WIRE AGITATES THE TONER IN THE HOUSING DURING THE MOVEMENT THEREOF AND ACCUMULATES A QUANTITY OF TONER THEREON, 